If you leave the page you're downloading from open and on that page (don't go forward, don't go backward, just leave it there), if the server breaks the connection (and cooks the DL) you can restart the download where it left off by clicking the link a second time. This will only work if the browser window is left open and on that page to preserve that specific session.
You can have 900 other browser windows open and frolicking all over hell and back...Just don't touch that one.
I'd forgotten about that earlier because it's (kinda second nature) habit at this point any time I'm DL'ing something from one of the chronically overloaded Chinese servers.